A recent critical security vulnerability in the OpenSSL implementation (CVE-2014-0160, also known as “Heartbleed”) affects recent versions of Ubuntu.
It’s a good time to update your linux. =)
sudo apt-get update sudo apt-get upgrade
Then check your Openssl version.
If you see OpenSSL 1.0.1g 7 Apr 2014, then you are good now, stop and go get a beer.
If you see OpenSSL 1.0.1 14 Mar 2012, double check by issuing:
dpkg -l | grep ' openssl '
If you see 1.0.1-4ubuntu5.12, then you are good, get some beer now.
And yes, since some of your long-running processes may be using the old openssl, the safest thing is to reboot as well.
Ref: http://askubuntu.com/questions/444702/how-to-patch-the-heartbleed-bug-cve-2014-0160-in-openssl, http://askubuntu.com/questions/444702/how-to-patch-the-heartbleed-bug-cve-2014-0160-in-openssl/444829#444829